121861919131 has 4 divisors (see below), whose sum is σ = 122065362000. Its totient is φ = 121658476264.

The previous prime is 121861919099. The next prime is 121861919141. The reversal of 121861919131 is 131919168121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121861919131 - 2⁵ = 121861919099 is a prime.

It is a super-2 number, since 2×121861919131² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121861919141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101720536 + ... + 101721733.

It is an arithmetic number, because the mean of its divisors is an integer number (30516340500).

Almost surely, 2^121861919131 is an apocalyptic number.

121861919131 is a deficient number, since it is larger than the sum of its proper divisors (203442869).

121861919131 is an equidigital number, since it uses as much as digits as its factorization.

121861919131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203442868.

The product of its digits is 23328, while the sum is 43.

The spelling of 121861919131 in words is "one hundred twenty-one billion, eight hundred sixty-one million, nine hundred nineteen thousand, one hundred thirty-one".